expanded xml for edge in order to support coloring of edges
changed EdgeWriter to class, created EdgeStyler for styling edges.
added EdgeStyle as an argument to the EdgeWriter, along with a default argument
the edge styl now actually depends on the EdgeStyle provided by the styler
implemented styler based on a predicate
wrapped the release plugin in an exception handler so that the build script works without network as well
new constructor for Writer for providing an edge styler
a graph now provides a list of edges that are part of circles. This is to be a considered a prototype of the final version which will provide a list of edges to break in order to get a cycle free graph ... and this for the different slices